| 摘要 |
<p>PURPOSE:To prevent deterioration of emission by setting skip quantity in storage item to be reduced at the time of judging deterioration of catalytic converter rhodium in a unit in which the air-fuel ratio of an internal combustion engine is regulated on the basis of rough regulation item and storage item. CONSTITUTION:When the output of an air-fuel ratio sensor A disposed on the lower stream side of a catalytic converter rhodium disposed in an exhaust system is reversed, proportional control is executed, and when the output is not reversed, integral control is executed to calculate B the rough regulation item of air-fuel ratio correction quantity. Further, when the output of the air-fuel ratio sensor A is less than a first threshold, and the output of the air-fuel ratio sensor A is a second threshold or more, at least the proportional control is executed to calculate C the storage item of the air-fuel ratio correction quantity. The air-fuel ratio of the internal combustion engine is regulated D on the basis of the rough regulation item and storage item. A catalytic converter rhodium deterioration judging means E for judging the degree of deterioration of the catalytic converter rhodium is provided, and according to the degree of deterioration of the catalytic converter rhodium, the skip quantity used for the proportional control in the storage item is set F small as the deterioration of the catalytic converter rhodium is large.</p> |
